1. Technical Field
The present invention relates to a power steering apparatus.
2. Related Art
In an electric power steering apparatus for a vehicle, before the electric power steering apparatus is assembled together, the adjustment of a shaft-to-shaft distance between a worm gear and a worm wheel is required to be simply done without being affected by dimensional errors of components such as the worm gear. Even when the meshing of the worm gear and the worm wheel changes over time after the assembly, it is necessary to simply adjust the shaft-to-shaft distance, and thus eliminate backlash between the worm gear and the worm wheel.
For example, Patent Literature 1 (JP-B-3646205) discloses an electric power steering apparatus having preloading means by which a bearing supporting a tip shaft portion of the worm gear is biased in a predetermined preload direction in such a manner that a preload is exerted on a meshing portion between the worm gear and the worm wheel. Due to a biasing force exerted by the preloading means, the shaft-to-shaft distance between the worm gear and the worm wheel is adjusted, and backlash therebetween is eliminated.